On Wednesday morning three Palestinians were shot dead in Jerusalem’s Old City, in occupied East Jerusalem, after carrying out an armed attack that left one Israeli police officer dead and injured another, Israeli police spokesperson Micky Rosenfeld confirmed.

The three Palestinians were shot dead at the scene after the attack, according to Rosenfeld, who said the attacks were carried out with knives and an automatic weapon. Explosive devices were later found at the scene.

A preliminary investigation revealed that it remains uncertain whether the police officer shot first or the attackers did, Haaretz has reported.

The police officers were 19 year old Hadar Cohen, who was shot in her head and pronounced dead later at Hadassah hospital, and an 18 year old, who remains in a critical condition.

The three Palestinian killed were identified as Ahmad Rajeh Ismail Karaneh, Muhammed Ahmad Hilmi Kamil, and Najeh Ibrahim Abu al-Rub, all from the village of Qabatiya near the occupied West Bank city of Jenin.

Israeli media reported that all three crossed into Israel illegally, and that none of them were affiliated with any political organization.

After the attack, Israeli forces raided the village of the three Palestinian youth who carried the attack, Qabatya, Ma’an News Agency reported.

During the raid, four Palestinian youth were shot and injured with live bullets and 15 year old Mujaded Zakarneh was run over with a military jeep. The 5 Palestinians were all evacuated to a local hospital for treatment and are in critical condition.

Israeli forces also raided the homes of the families of the three Palestinians who carried the attack in occupied East Jerusalem’s Old City, and notified them that their homes would be demolished.

Qabatiya was later designated a closed military one, and it will remain a closed zone for at least month, with all its entrances closed to passage in or out of the village.

An Israeli army spokesperson said that, “in accordance with the government’s directives, forces entered the village in order to assess the localities of the residences’ of the three assailants who killed a border police officer in Jerusalem.”

“Security measures have been taken in the village in accordance with situation assessments, which means entrances and exits are closed with exception of humanitarian cases,” the spokesperson added.

At least 12 Palestinians were detained during the raid, including two from outside villages and the father and brother of one of the East Jerusalem attackers. Some of them remain unidentified.

The attack on Wednesday is part of a wave of unrest that started in October 2015 in the occupied city of East Jerusalem and spreaded across the occupied Palestinian territories and Israel. Over 160 Palestinians and 20 Israelis have been killed over that period.